Although an enormous amount of time and effort has been spent on physiological studies of the anterior pituitary gland, relatively little attention has been devoted to internal regulatory mechanisms within this tissue. The primary objective of this research proposal will be to determine whether intrahypophyseal regulatory mechanisms exist among the various cell types within the pituitary gland. In vitro hormone production will be evaluated in cell populations which have been artificially contstructed by cell separation techniques. The specific objectives are: 1) to determine whether follicular cells can alter pituitary parenchymal cell function and 2) to determie whether cell-cell interactions between mammotrophs and gonadotrophs have any bearing on hormone secretion in these cells. An understanding of specific intrahypophyseal control mechanisms may broaden our knowledge of hypothalamic-hypophyseal regulation during both normal and pathophysiological states.